Tool



SePf.23, 1941. w. osENBERG 2,256,847

' Toon Filed Sept. '7, 1937 Patented sept. 23, 1941 TOOL Werner Osenberg, Dresden, Germany, assignor to Kerb-Konus Gesellschaft Dr. Carl Eibes & Co.,

Dresden, Germany Application September 7, 1937, Serial No. 162,757

In G

12 Claims.

The present invention relates to a new and improved tool for cutting, milling, drilling, grindmetal alloys or the like, the softer metal and also in some cases the harder metal.

ermany 4December 15, 1936 (C1. asa- 95) It is a further object of the inventionto devise l hard porcelain but may be applied to tools of any I desired material. As is obvious howeverl the connection points between successive cutting edges must be adjusted tothe type of material used and if recesses are used between successive cutting edges then in such case these recesses must be of such size as to correspond with the strength of the material used in order to permit the removal cf cutting edges that have become blunt or unserviceable or undesirable for any reason.

A further object of the invention is to provide a tool wherein the holder therefor is made integral therewith. In such case the tool is given its denite shape in the raw material before baking so that subsequent treatment to give it the actual tool form is not Inecessary as is, for example,

, always the case with tools made of metal.

the working surfaces-become worn or damagedv -while at the saine time also providing the possibility of bringing into operation differently proled working surfaces one after the other so as to perform various kinds of work with one and the same tool. 4

An additional object isto provide a construction in the tool whereby the replacement of the working surfaces by subsequent 'working-surfaces may be automaticallybrought about by the operating conditions themselves lor may be substituted in place of the former operating surfaces s it is more advantageous to simply replace the,

by breaking o the support of such former oper- K ating surfaces at a desired position. y

A-further purpose is to provide weakened por tions in the material of the tool between the support for the first operatingsurfaces and the I. supports of subsequent operating surfaces and utilizing these weakened portions for facilitating' the-breaking olf of the support of the rst operating surfaces or making such severance obligatory at certain operating pressures.

In order to permit the tool of the character indicated to present a smooth outer surface which is essentially necessary in tools of disc shape such weakened portions, which may take the form of recesses, are lied with asofter ceramic material, a soft metal or an articial compound s uch as an articial resin composition or the like.-

Furthermore the invention is not restricted to A further object of the invention is to provide a tool made from material which is exceedingly cheap so that a resharpening of the operating surfaces,- which although often practicable, may be dispensed with, since it has been found that worn out tool with a new one.l

A further object of the invention is. to manufacture tools of the kind indicated which consists mainly in shaping them and then subsequently baking them but at the same time providing such tool with several operating surfaces displaced with respect to each otherand which operating surfaces may be produced in the same process Without any further expenditure in labor, etc. On wear taking place in tools of this character,

these working or operating surfaces may be made use of successively by merely turning the tool in its holder.

An additional object is to provide operating surfaces which are different in designso that various types of work may be performed by one and `the same tool by making successive use of such differently designed operating surfaces. Y For instance, one operating surface could accomplish the rough planing while a successive surface accomplishes a fine planing and then a still further successive surface would polish the object operated upon.

A further object of the invention is to providev ya tool ofthe material indicated wherein such tool is provided with two or more operating surfaces located in back of one another in the direction of operation and in which the operating surface that i'lrst comes into operation consists of a part ofthe tool that is made from hard ceramic material. The second working surface may also consist of a part of the tool that is made .from hard ceramic material, howevr, in uns instance the second or subsequent operating surface may be made of steel. Of course the parts of the tool provided with the different working surfaces are kept constructionally separate from one another and as regards their operating surfaces such surfaces are separately positioned adjustably in a tool holder.

With these and other objects in view which will become apparent from the detailed descripcated under the cutting edge.

F'lgureGisapartialplanview ofthetool shown in Figure 5.

Figure'lisapartiaicrosssectionalviewofthe modification shown in Figure 5 illustrating recesses which do not entirely penetrate the tool.

Figureisapartialelevationalviewofahoi- Y low drill. Figure 9 illustrates the invention as appliedto adrilloramillingtypeoftoolandtheviewshows the same in partial elevation.

Figure 10 is an elevational view with portions in cross section illustrating the invention as applied'to a thread Flgurellisapianvlewofthethreadchaser shown in Figure 10.

Figure 12 is an elevational view of a further modication illustrating the invention as applied to a grinding or milling wheel.

In the drawing like reference characters will be used to indicate like parts.

A basic feature of the invention resides in the type of material from which the 'xerf removing tools are made. Tools of the type indicated have never heretofore been made from this material.

'111e hard ceramic raw material in puiverized form or the like may be combined with a suitable ceramic binding agentfto'form a hard substance' from which the tools are manufactured with subsequent baking or the ceramic raw material such as corundum may be transformed by vitrification intoahardsubstancewhichisdirectlyformedin theshapeofthetooldesired. f

Theceramicrawmaterialmaybeeitherana urallyexisiangsubstanceoronethatisproduced artificially by ilrst'manufactm'ing a ceramic raw materiaibybakingorfusingasforexampiein an electric furnace and thcnconverting it by trituration into powderA form or the like and then this material in pulverized form is treated in Veither of the two ways set out immediately above.

The natural raw materials comprise hardceramc substances such as corundum, flint or the like. The artiiicial materials comprise a material produced in theelectric furnace from pure bauxite, the slag produced from alumina in the thermal process, carborundum, carbosilite, which consists of silicon carbide, which is manufactured in theelectric furnace from quartz and coke and also boron carbides. Other raw'materials that .may be mentioned are the oxides of zir.

conium and magnesium-aluminium compound.

As a binding agent kaolin may be mentioned as an example. Obviously one of the above mentioned substances may also be used as a binding agent providing a ceramic material that is more dimcult to fuse is selected as the base material. For instance, a thorium oxide, which hasa melt`` ing point of about 3,000" C. could be combined in accordance with the rst method set out above with zirconium oxide which has a melting point of about 2700* C. In this case the zirconium oxide would act as, the binding agent.

The importance of` the present invention resides inthe use of a hard material of the above generally defined ceramic nature for tools such as cutting tools, millers, drills, reamers, illes or the like.

The application of such a material to tools of various types shown in'the drawing will now be described in detail.

In Figure 1 a cutting tool is indicated at I which is provided with the recesses 2. 'I'he cutting edge is shown at 3. When the cuttingedge '2 becomes damaged or worn for any reason then Y cated between them is broken off that a good Furthermore the re.

cutting edge should result. cesses 2 may also be used for supplying a cooling medium to the cutting point.

In Figure 3 there is illustrated a rotary cutter 2l which is provided with the diiferently shaped cutting profiles 2l, 22 and 23 positioned one in back of the other. In this case as the cutting tool is broken of! at the r a modified or diiferently shaped cutting surface is exposed. Due to this construction different cutting operations may take place upon the object being operated upon.

In Figure 4 a slight modication is shown in a rotary cutter 24. In this case notches 2l are located in alignment Vwith the recess I0 and apertures 28 are provided in alignment with the re- 4 cess Il. The notches 25 or the apertures 26 will facilitate the breaking of! of the cutting tool at the particular recs desired. As is obvious any particular tool of this type may be provided with notches similar to the notches 25 extending throughoutA the entire length of the tool whereever recesses are provided or 'instead of the notches 25 apertures 2l may extend throughout the length of the tool at the recess positions.

AIn Figures 5, 6 and 7 there is illustrated a tool 4 in which a polishing element t isI provided on the tool located under the cutting edge 5. As particularly indicated in Figures 6 and? the recesses t2 are located in back of each other but instead of passing entirely through the tool terminate short of the bottom thereof in order to,l increase the strength of the tool.

and the exposing of the new cutting edge. When an old cutting edge is broken of! a` polishing member which may be formed of the material itself However tools designed' with recesses such as .42 will also permit the breaking off of the worn or damaged cutting edge The hollow` bore of the drill il indicated at 43 and in this case the recesses at which the drill is to be broken oif for the purpose of exposing new cutting edges is indicated at 44.

In Figure 9 there isillustrated .a1 drill or a milling type of tool 8 in which the bottom teeth 45 oper-ate upon the object being treated. 'I'he teeth have a bottom inclination as shown at 38 In Figure 12 the invention is shown applied toa tool I which is in the form of a grinding wheel. The operating prole is shown at II.

This same operating proiile may be continued throughout the entire tool but in the form shown in Figure 12 various dierent designs of cutting profiles are shown which may be for different types of work desired done by the tools. The recesses 49 provided in the tool may be designed in such a way ascesi?- which assist the recesses 46 in the severancel of that the breakingoff of the intermediate. ma-..

terial in back of the blunt or damaged cutting edge will either expose a cutting edge of the same type or if desired one of an entirely different design such as shown at I 2. for instance, which is formed by a recess having a general configuration shown -at I3. The cutting edges on a tool of the type shown in this figure must be arranged in saw tooth zig zag pattern in order t0 provide a clean cut. In so far as the grooves or -constructions are disposed for the support of the parts to be broken off, they must be given such dimensions that the tool will retain the necessary strength and the position thereof must be so selected that good outing edges are always provided after the breaking oif of the blunt or worn cutting edges. For this purpose as shown in figure 12 the curved limiting line I4 for the recesses 49 extend over the points of the teeth I 5. Tools of such a disc shape can to a certain extent sharpen themselves by starting the disc against the object being operated upon with a suitably heavy pressure. By starting the tool in this way damaged or partially destroyed cutting edges will break of! until the next cutting edge provided by the recess is exposed. It is of course also possible to cause the breaking ofi' to take place by the use of tools such as pliers, etc. Also the breaking oil' may be accomplished by driving conically shaped pins into the holes in the tools or chisels may be applied to notches which have been-provided.

1. A tool comprising essentially a body of ceramic material, a cutting edge provided thereon, said body having a recess located in back of said cutting edge of such configuration that when the portion of said body containing` said cutting edge is removed a newlcutting edge constituting a wall of said recessie exposed.

va. A tool comprising a body or ceramic material. a cutting edge provided thereon, said body having a recess located in back of said cutting edge of such configuration that when the portion of said body containing said cutting edge is removed a new cutting edgeI constituting a wall of said recess is exposed, and said recess being so disposed as to form weakened portions to facilitate theremoval of the portion of said body containing said iirst-mentioned cutting edge.

3. A rotary cutting tool comprising a body^of4 ceramic material, cutting edges upon the periphery of said tool and said body having recesses which denne interior new cutting edges when the peripheral cutting edges are removed'.

4. A tool comprising a body of ceramic material, working profiles on said body and recesses in said body arranged in back of one another defining new working profiles of varying characteristics.

5. A hollow drill comprising a body of ceramic material and recesses in said body defining additional new cutting edges upon the removal of the exterior cutting edges.

6. A drill comprising a body of ceramic mate- I rial and cutting points upon said body located in located in back of one another andhaving-ai series of weakened portions so that blunted outting edges may be severed from the body and thereby expose new cuttingv edges.

8. A method of making a tool" comprising forming a body of ceramic material having recessestherein defining cutting edges, said recesses having been formed within said -body during the baking process by burning combustible material of the desired configuration.

. k 9. A tool comprising a body made of ceramic material, a plurality of working surfaces on said body displaced with,A respect to one another so that said working surfaces may be brought into consecutive service by-a corresponding turning o1' said tool in a holder.

10. A tool comprising a body of hard ceramic material, a central at surface upon said tool designed to cooperate with a holder for said tool and a series of cutting surfaces upon said tool formed by concavities extending from said central flat surface to the peripheral edge of said tool.

working surfaces located one in back of each other in the direction of operation and the working surface which first comes into action lbeing made of hardceramic material.

terial.

another and said working surfacesbeing such asv to be separately adjustable in a tool holder and said members beingmade of a hard ceramic ma- WERNER OSENBERG.

1l. A kert removing tool having a plurality of 

